Protein microarrays with carbon nanotubes as multicolor Raman labels.
The current sensitivity of standard fluorescence-based protein detection limits the use of protein arrays in research and clinical diagnosis. Here, we use functionalized, macromolecular single-walled carbon nanotubes (SWNTs) as multicolor Raman labels for highly sensitive, multiplexed protein detection in an arrayed format. Unlike fluorescence methods, Raman detection benefits from the sharp scattering peaks of SWNTs with minimal background interference, affording a high signal-to-noise ratio needed for ultra-sensitive detection. When combined with surface-enhanced Raman scattering substrates, the strong Raman intensity of SWNT tags affords protein detection sensitivity in sandwich assays down to 1 fM--a three-order-of-magnitude improvement over most reports of fluorescence-based detection. We use SWNT Raman tags to detect human autoantibodies against proteinase 3, a biomarker for the autoimmune disease Wegener's granulomatosis, diluted up to 10(7)-fold in 1% human serum. SWNT Raman tags are not subject to photobleaching or quenching. By conjugating different antibodies to pure (12)C and (13)C SWNT isotopes, we demonstrate multiplexed two-color SWNT Raman-based protein detection.
Chen
Zhuo
Z
Department of Chemistry and Laboratory for Advanced Materials, Stanford University, 333 Campus Drive, Mudd Building, Room 121, Stanford, California 94305, USA.
Tabakman
Scott M
SM
Goodwin
Andrew P
AP
Kattah
Michael G
MG
Daranciang
Dan
D
Wang
Xinran
X
Zhang
Guangyu
G
Li
Xiaolin
X
Liu
Zhuang
Z
Utz
Paul J
PJ
Jiang
Kaili
K
Fan
Shoushan
S
Dai
Hongjie
H
D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D002247:Carbon Isotopes / Q000737:chemistry; D002250:Carbon Radioisotopes / Q000737:chemistry; D014890:Granulomatosis with Polyangiitis / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D051379:Mice; D053146:Myeloblastin / Q000276:immunology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D040081:Protein Array Analysis / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D001323:Autoantibodies; D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D037742:Nanotubes, Carbon; D053146:Myeloblastin